There has long been a need for an accurate and easily usable tension tester for drive belts and the like, particularly in the vehicle manufacturing industry. Belts have been extensively used on vehicle engines to power accessory devices such as alternators, air conditioning compressors and power steering pumps. With the more common use of overhead cam systems, belts have been used to rotate the cam. In all of these applications, it is important that the belts be tensioned correctly. If the belt is too loose, it will slip and maybe make an undesirable noise. If the belt is too tight, its durability will be decreased and excessive stress will be exerted on the associated bearings.
An example of a previous patent on a belt tension gauge is U.S. Pat. No. 4,444,065 to Okamuro. This gauge has a manual handle type activator which is moved against a lever arrangement to cause a member to press downward against a belt. A mechanical gear and rack type of gauge is disclosed in the Okamuro patent.
A second patent on a belt tension gauge is found in U.S. Pat. No. 2,996,914 to Delehanty. The Delehanty patent discloses a tester much like the Okamuro device described above. However, instead of pressing downward on the belt, this device pulls the belt upward toward the tester. The read-out gauges in the two patents are similar.
The following three patents were uncovered which relate to belt tension measuring devices. The U.S. Pat. Nos. are: 3,352,153 to Howard; 3,596,508 to Howard and 3,564,913 to Evans. et al.
The following three patent were uncovered which relate to tension measuring devices for other devices than belts and the like. The U.S. Pat. Nos. are: 2,528,883 to Hayward for measuring the weight on a drilling bit; 3,720,100 to Grunbaum for measuring the tension of filaments or the like; 4,077,256 to Hollander for measuring the tension of a stringed racket.